Fractional dial computer



Feb. 2o, 1968 A. F. MERz 3,369,745

FRACTIONAL DAL COMPUTER Filed April l0, 1967 f/V VEN 7-'0/2 KEA/045 MEEZ United States Patent O 3,369,745 FRACTIONAL DIAL COMPUTER Arnold F. Merz, Port Alice General Delivery, British Columbia, Canada Filed Apr. 10, 1967, Ser. No. 629,766 1 Claim. (Cl. 23S- 78) ABSTRACT F THE DISCLOSURE A computer for adding and subtracting fractional numbers, including a pair of different sized circular discs centrally pivoted together, each disc being graduated in one sixty-fourth of an inch digits around its edge, and the graduations of one disc being in adjacent alignment position with the graduations of the other disc.

This invention relates to pocket computers. More specifically it relates to computers fory adding and subtracting fractional numbers.

A principal object is to provide a fractional dial computer for adding and, or, subtracting fractional numbers and which will speed up the calculation of fractions on a blue print with chain measures, such as on a length of shafting.

Another object is to provide a fractional dial computer which may be readily and conveniently carried in the pocket, and which is adaptable 4for use in machine shops, drafting and engineering departments of organizations, and the like.

Another object is to provide a `fractional dial computer which requires no mathematical skill to interpret blueprints, and which does not require a pencil to calculate resultant totals.

Other objects are to provide a fractional dial computer which is simple in design, inexpensive to manufacture, rugged in construction, easy to use and eflicient in operation.

These and other objects will be readily evident upon a study of the following specification and the accompanying drawing wherein:

FIGURE 1 is a front faceview of the present computer,

FIGURE 2 is an edge view thereof,

FIGURE 3 is a fragmentary face view of a modified form of the invention, and

FIGURE 4 is a cross-sectional view taken on line 4-4 of FIGURE 3.

Referring now t0 the drawing in detail, the reference numeral represents a fractional dial computer according to the present invention wherein there is a larger lower dial 11 and a smaller upper dial 12, each of circular configuration, the dials being concentrically secured together, pivotally free by a rivet 13.

The lower dial 11 has a circular top face 14 bounded by a peripheral edge 15; the face 14 having a plurality of radially extending graduations 16 and fractional designations 17 imprinted thereupon.

The upper dial 12 likewise has a top -face 18 bounded by circular'edge 19; the face 18 having a plurality of radially extending graduations 20 and fractional designations 21 imprinted thereupon.

The designation on each of both dials comprises fractions of one sixty-fourth of an inch, and the graduations for the fractions are spaced equally apart around each of the dials. A transparent pointer 22 with hairline 23 aids in aligning a reading.

In operative use, to add a fractional number to another, a person must line up the graduation of one of the nurn- ICC bers on the lower dial with the zero graduation of the upper dial, the other number on the upper dial thus aligning with the total on the lower dial. For example to add /s to 74,4, line up the 1A; digit on the lower dial with the Zero on the upper dial; the digit 7A, on the upper dial lining up with the total 1%4 on the lower dial. To subtract, reverse the process.

If the addendum line 24 on the upper dial passes the zero line on the lower dial during anti-clockwise movement, add one whole number to the sum. If the zero line of the upper circle passes the zero line of the lower circle during clockwise movement, subtract one whole number from the sum.

A modified computer 2S, shown in FIGURES 3 and 4 includes a lower dial 26 having upward pressed protrusions 27. The upper dial 28 has upward pressed dimples 29, the dial being upwardly dished as shown at 30 and being radially slotted as shown at 31. When at rest, the upper dial is upwardly dished as shown by the soled lines in FIGURE 4, at which time the protrusion engages the dimple to prevent accidental turning of the dials relative to each other. To rotate the dials, the upper dial is depressed at its center, as shown by phantom lines in FIGURE 2, thus causing displacement outwardly of the dimple from the protrusion `and allowing the dials thus to turn relative to each other. The slots 31 allow depression of the dial and the radially outward travel of the dimples.

The novel features and the operation of this device will be apparent from the foregoing description. While the device has been shown and the structure described in detail, it is obvious that this is not to be considered limited to the exact for-m disclosed, and that changes may be made therein within the scope and the spirit of the invention.

Having thus set forth and disclosed the nature of this invention, what is claimed is:

1. In a fractional dial computer, the combination of a larger lower dial, a smaller upper dial, each said dial comprising a circular llat disc, said dials being concentrically secured together pivotally free relative to each other on a rivet, each said dial having radially extending graduations spaced equally apart and each said graduation having a fractional designation, said designations comprising one sixty-fourth of an inch readings around said disc from zero up to one inch, and a concentrically pivoted pointer, wherein said readings progress from zero upwardly in a counter clockwise direction, wherein said lower dial has a plurality of upward extending protrusions engaged within upward extending dimples on said upper dial when at rest, said upper dial being upwardly dished and radially slotted to permit downward depression of said upper dial and radial outward travel of said dimples to disengage with said protrusions to allow rotation of said dials relative to each other.

References Cited UNITED STATES PATENTS 198,934 1/1878 Fields 23S-131 447,803 3/1891 Winter 116-133 1,211,581 1/1917 Henoch 235-84 1,455,339 5/1923 Keller et al. 235-84 2,223,612 12/ 1940 Grundlehner 235-78 2,237,873 4/1941 Barok 23S-78 RICHARD B. WILKINSON, Prmaly Examiner.

S. A. WAL, Assistant Examiner. 

